The present invention relates to semiconductor manufacturing technology, and more particularly to MEMS devices and a method of manufacturing such MEMS devices.
With the continuous development of semiconductor technology, integrated CMOS devices and micro-electromechanical system (MEMS) devices have increasingly become the main stream and the most advanced technology in the market of sensors (motion sensors). With the technological advance, such motion sensors are getting smaller and have high electrical performance with reduced wear and tear.
Conventional process steps of manufacturing a MEMS device are shown in FIGS. 1A, 1B and 2A through 2C. As shown in FIG. 2A, a conventional manufacturing process step may start with separately providing a MEMS substrate 101 and a cover layer 102. The MEMS substrate may have multiple sensor devices and aluminum pads, which will be used to encapsulate the MEMS device.
Next, the MEMS substrate 101 and the cover layer 102 are bonded together to form the MEMS device, as shown in FIG. 1A and FIG. 2B.
Thereafter, the covering layer 102 is submitted to scribing and cutting (blade dicing) to reduce the size of the covering layer 102 and expose the bonded substrate, as shown in FIG. 1B and FIG. 2C.
Cutting the cover layer with a dicing saw blade generates silicon dust that falls on the surface of the bonded substrate, resulting in pad corrosion.
In order to remove the silicon dust generated during the cutting (dicing) process, the cutting process relies on the increase of the water flow rate to increase the momentum, however, the rinsing with high water flow rate leads to a dummy pattern fall down, thereby reducing the product yield and performance of the MEMS device.
Thus, there is a need for a method of fabricating a MEMS device that prevents the above-described problems of the prior art.